By E. Cruz. The Rockefeller University.

The red cell normally survives in the blood stream for approximately 120 days after which time it is removed by the phagocytic cells of the reticuloendothelial system discount hytrin 1 mg amex hypertension diet plan, broken down and some of its constituents re utilized for the formation of new cells cheap hytrin 5 mg line hypertension nih. White Blood Cells They are a heterogeneous group of nucleated cells that are responsible for the body’s defenses and are transported by the blood to the various tissues where they exert their physiologic role, e. These are: • Polymorphonuclear leucocytes/granulocytes o Neutrophils o Eosinophils o Basophiles • Mononuclear leucocytes oLymphocytes oMonocytes Fig. Basophiles have a kidney shaped nucleus frequently obscured by a mass of large deep purple/blue staining granules. Their cytoplasmic granules contain heparin and histamine that are released at the site of inflammation. Mononuclear Leucocytes Lymphocytes There are two varieties:  Small Lymphocytes Their size ranges from 7-10µm in diameter. Their cytoplasm stains pale grayish blue and contains reddish blue dust-like granules and a few clear vacuoles. They are capable of ingesting bacteria and particulate matter and act as "scavenger cells" at the site of infection. Platelets These are small, non nucleated, round/oval cells/cell fragments that stain pale blue and contain many pink granules. They 8 Hematology are produced in the bone marrow by fragmentation of cells called megakaryocytes which are large and multinucleated cells. When blood vessels are injured, platelets rapidly adhere to the damaged vessel and with one another to form a platelet plug. During this process, the soluble blood coagulation factors are activated to produce a mesh of insoluble fibrin around the clumped platelets. This assists and strengthens the platelet plug and produces a blood clot which prevents further blood loss. It also carries nutrients from the gastrointestinal tract to the cells, heat and waste products away from cells and hormones form endocrine glands to other body cells. It also adjusts body temperature through the heat-absorbing and coolant properties of its water content and its variable rate of flow through the skin, where excess heat can be lost to the environment. Blood osmotic pressure also influences the water content of cells, principally through dissolved ions and proteins. In postnatal life in humans, erythrocytes, granulocytes, monocytes, and platelets are normally produced only in the bone marrow. Lymphocytes are produced in the secondary lymphoid organs, as well as in the bone marrow and thymus gland. Although many questions 10 Hematology remain unanswered, a hypothetical scheme of hemopoiesis based on a monophyletic theory is accepted by many hematologists. According to this theory, the main blood cell groups including the red blood cells, white blood cells and platelets are derived from a pluripotent stem cell. The pluripotent stem cells may mature along morphologically and functionally diverse lines depending on the conditioning stimuli and mediators (colony-stimulating factors, erythropoietin, interleukin, etc. During fetal life, hemopoiesis is first established in the yolk sac mesenchyme and later transfers to the liver and spleen. The splenic and hepatic contribution is gradually 11 Hematology taken over by the bone marrow which begins at four months and replaces the liver at term. From infancy to adulthood there is progressive change of productive marrow to occupy the central skeleton, especially the sternum, the ribs, vertebrae, sacrum, pelvic bones and the proximal portions of the long bones (humeri and femurs). Hemopoiesis occurs in a microenvironment in the bone marrow in the presence of fat cells, fibroblasts and macrophages on a bed of endothelial cells. An extracellular matrix of fibronectin, collagen and laminin combine with these cells to provide a setting in which stem cells can grow and divide. In the bone marrow, hemopoiesis occurs in the extravascular part of the red marrow which consists of a fine supporting reticulin framework interspersed with vascular channels and developing marrow cells.

A sample may be obtained in a process called amniocentesis by putting a needle through the skin of the lower abdomen and into the uterus and drawing off a small amount of amniotic fluid quality hytrin 1 mg blood pressure medication bruising. The amniotic fluid is created by the urine and faeces of the foetus buy 1mg hytrin amex hypertension 4th report, and by secretions from the placenta. The foetus is constantly swallowing and processing the fluid from about 15 weeks onwards, and it aids the growth and nutrition of the foetus. The dark colouration may only be noticed at the beginning of labour when the waters break with the rupture of the amniotic sac in which the fluid and foetus are contained. The volume of amniotic fluid steadily increases throughout pregnancy until about 36 weeks, after which it slowly decreases. Hormones and waste produced by the foetus are also present as these are excreted in the urine of the foetus. It is attached to the edges of the placenta and otherwise is pushed against, but not attached to, the inside of the uterus. The procedure is usually performed through the vagina and cervix with a pair of toothed forceps that are used to grasp and tear the membrane. Antenatal care involves regular visits to a doctor or nurse from the third month of pregnancy onwards. During these visits appropriate blood and ultrasound tests will be ordered when necessary, and the mother’s urine will be tested. Other checks on the mother and baby’s health will also be performed depending on the stage of pregnancy, and may include weight, blood pressure, checking for swollen ankles and feet, checking the size of the uterus, listening for the baby’s heart beat, checking the baby’s position and feeling the baby’s movements. The score is derived by giving a value of 0, 1 or 2 to each of five variables - heart rate, breathing, muscle tone, reflexes and colour. By the age of 18 months a girl is usually half her adult height, and a boy is by the age of two years. Many children grow quickly and then stop early so that they are short, whereas others seem to grow at a slower pace but continue until they outstrip everyone else. The most significant factor in determining height is heredity - the children of tall parents will usually also be tall. Nutrition is also significant, and a child who is poorly nourished is likely to be shorter than one who is well nourished. Advances in nutrition are the main reason for an overall increase in the height of populations of the developed world. At about four months, the baby will usually be able to sit up with support, and at the age of seven months should be able to sit alone. They can probably put one leg after the other if they are led at about 11 months, and pull themselves up on the furniture by one year. At about 14 months a baby can usually stand alone, and the major milestone of walking will probably occur around 15 months. Physical development does not equate with mental development, and parents should not be concerned if their child takes its time about reaching the various stages - Einstein was so slow in learning to talk that his parents feared he was retarded. Most newborn babies sleep most of the time - although there are wide variations and some babies seem to stay awake most of the day and night, to the distress of their parents. Gradually solids become an integral part of the diet, and by six months the amount of milk can usually be reduced in proportion to solids in each meal. If the baby is not breast fed, infant formula is recommended for most of the first year, although many babies cope with ordinary cow’s milk from six months. By the time a baby is a toddler, they should be eating much the same meals as the rest of the family, assuming these are nutritious and well balanced. Some parents become excessively anxious because their child seems to be a fussy eater, and they worry that the child will not receive adequate nutrition. This is usually because meals have become a battleground with a parent insisting on every last scrap being consumed.

Training in personal competencies and skills Personal problems and deficits are considered important risk factors discount 5mg hytrin mastercard blood pressure healthy value, since the adolescent can turn to drug use in an attempt to compensate for them order hytrin 5 mg mastercard hypertension lifestyle changes. Thus, stress and the lack of personal competencies or coping skills are important factors that promote drug use. Therefore, along with training in social skills is included training in other more general skills that strengthen individual resources to deal with any aspect of daily life. Some of the specific components included are: training in problem solving and decision making, setting goals and objectives, coping skills, emotional self- control (managing mood, anxiety and anger), self-reinforcement, public commitment regarding future drug use (non-use or responsible consumption), affective education (self-concept and self-esteem) and the promotion of alternative leisure activities to drug use. Again, note that the methodology used is based on active learning strategies and interactive teaching techniques that facilitate the acquisition of such skills. As we have previously seen, many school-based programs are enhanced by the inclusion of interventions in the family, the community, the media and the school system in a broad sense. In reference to the school climate or context, it is important to stress that the particular normative setting of schools plays a vital role since the probability that a given behavior (e. Therefore, it is essential to establish a "drug policy" that clearly defines rules and procedures about the consumption, availability and distribution of both legal and illegal drugs at the school and its surroundings. Similarly, the measures to take in the event of a breach of the prohibition against the use of tobacco, alcohol or other drugs by any member of the educational community should be clearly established. In this sense, a clear school policy on drug use, especially tobacco and alcohol, facilitates the active involvement of teachers, fostering among them a role of exemplar in relation to the use of drugs. In the same way, it is imperative that the implementation of a program be facilitated, not only by the support of the school but also by the settings closest to the students. Through the inclusion of activities that involve the family and community, the knowledge and skills learned are transferred and generalized to other contexts where students spend the rest of their time. And therefore, the likelihood that the produced positive effects are maintained over time is increased. At present, the debate about preventive drug use interventions focuses on identifying the school-based programs that have proven effective, as well as distinguishing the quality control measures and best practices for carrying them out. For which reason, it is recommended that only school-based programs that have proven effective in well-designed evaluation studies be applied. In this regard, and despite the fact that in previous decades the prevention of drug use has been characterized by an absence of rigorous assessments, today we have at our disposal a reliable list of numerous school-based programs that have proven their effectiveness in the school-age population (e. Conducting an assessment of the preventive programs that we put into practice is essential, because otherwise, unaware of the factors that influence their efficacy, we can only intuitively know whether these programs work. In this context, the evaluation of school-based programs should be considered a form of scientific research which must be carried out using methods that maximize the objectivity of its results. In short, evaluation consists of putting research tools at the service of the process of accurately and objectively judging the value of a program. Nevertheless, in spite of the large variety of typologies that have been proposed throughout the literature, such contributions can be drawn together into four levels of evaluation that are initiated even before designing or selecting the school-based program to apply: Needs assessment. In the school-based context, this first step consists of determining the prevalence and incidence of drug use in the school population, as well as the risk and protective factors present. By means of this phase, the relevance and adequacy of the program to develop is assessed 25 School-based Drug Use Prevention To proceed to these aims we can utilize various sources (e. Notwithstanding, by offering a comprehensive and updated overview of the patterns and trends of drug use, epidemiological studies are an important source of information in the field of drug prevention. It is performed during the application of the program in order to make improvements on and assess the adequacy of its implementation.